Following Börje Salming’s ALS diagnosis, experts say more research needed into dangers of head injuries

News that Toronto Maple Leafs icon Börje Salming has ALS has emerged amid growing research into the disease’s prevalence among athletes as well as into its potential connection with the type of head trauma that many suffer through their careers.

It isn’t known at this point whether Salming’s two decades as a hockey star have any relation to the diagnosis the 71-year-old has now shared publicly.

Yet researchers are increasingly looking at the kind of impacts that cause concussions — and at those head injuries that may not show any symptoms at all in the moment. They say research needs to continue in order to keep today’s athletes safe.

Salming announced Wednesday that he had be diagnosed with ALS, which stands for amyotrophic lateral sclerosis. Salming played 16 seasons with the Maple Leafs from 1973-89 and was inducted into the Hockey Hall of Fame in 1996.

ALS, also known as Lou Gehrig’s disease, is characterized by loss of muscle control that eventually leads to complete paralysis. Life expectancy from symptom onset is typically about two to five years. There is no cure, but there are treatments available that aim to slow the disease.

Dr. Daniel Daneshvar, a neuroscientist who is an assistant professor at Harvard Medical School and a brain injury physiatrist at the Massachusetts General Hospital Brigham network, said that since 90 per cent of ALS cases are considered “sporadic” — meaning researchers don’t know their origin — it’s been paramount for scientists to investigate the causes of ALS.

And one of the identified risk factors is traumatic brain injury, he said.

Severe head injuries causing concussion are a factor, but so too are repeated head injuries that may not have resulted in any symptoms at all, he explained.

“At this point, we’re still working on proving that relationship, but it’s pretty convincing that the underlying common denominator between these athletes at higher risk of ALS and athletes that don’t, are a history of repetitive head impacts,” he said.

Daneshvar said research following soccer players and the connection to ALS first started emerging in the early 2000s. Recent studies have also shown a connection between head trauma and ALS in soccer players and football players.

A study from 2019 published in the New England Journal of Medicine showed that soccer players were four times as likely as a control group of nonplayers to have their cause of death be motor neuron disease — a disease category ALS falls under.

When it comes to football players, Daneshvar points to a paper he and several other academics wrote that was published in 2021 in the Journal of the American Medical Association. It found that NFL players who debuted between 1960 and 2019 were four times as likely to be diagnosed and die due to ALS than members of the general population.

“The common denominator between the football players and the soccer players is they both get these non-concussive hits to the head, so the kind of hits that don’t cause symptoms, but that occur to the tune of hundreds of times during a season,” he said.

“Those are the hits we believe are responsible for the neurodegenerative processes,” he said.

The protein associated with the development of ALS, called TDP-43, is seen in the brains of those with the disease who had repeated head trauma, Daneshvar explained. “The thought process is that when this protein builds up in the wrong places at the wrong time, that might cause someone to develop ALS.”

There isn’t enough research on hockey players yet, Daneshvar said. There are hopes that research will continue for athletes and groups such as survivors of domestic violence, where repeated heat trauma continues to be an issue.

Tim Fleiszer, the executive director of the Concussion Legacy Foundation, an organization that supports people, including athletes, who are affected by concussions and CTE — Chronic Traumatic Encephalopath, a fatal disease caused by repeated injuries to the brain —said it’s unfortunate that so many former athletes are being diagnosed with a rare disease.

There are about 3,000 Canadians who live with ALS. About 1,000 die each year of the illness and another 1,000 are diagnosed annually, according to the ALS Society of Canada.

Fleiszer, who is also a former CFL player and multiple-time Grey Cup champion, said it’s crucial to modify sports to prevent this type of injury, particularly for kids under the age of 14.

“You know, not exposing children to tackle football, not exposing (them) to body checking in hockey, not exposing (them) to headers in soccer, you do that and you’ll significantly reduce the risk of these disease progressing later in life,” he said.

Chris Nowinski, a co-founder and CEO of the Concussion Legacy Foundation, former football player and WWE professional wrestler who has dealt with head trauma from sports, said he and Fleiszer have watched teammates die recently of head trauma-related causes and that the link between ALS and head injuries needs to be taken more seriously.

“It’s another reminder that this is preventable, repetitive head impacts are entirely preventable in sports.”